tie (oneself) in(to) knots
1. To make oneself confused, anxious, worried, and/or upset, as when trying to make a decision, come up with an idea, or resolve an issue. Now don't go tying yourself into knots over the details of your papers—at this point, all you need is a cohesive outline. We've tied ourselves in knots this past week trying to choose who to hire, but I think we've reached a decision.
2. To befuddle oneself while attempting to explain something (to someone). Primarily heard in UK. Jim's a smart guy, but for some reason, he always ties himself into knots whenever I ask him to explain something on the computer for me.